PCB for a Double Horse 9088

[peeteey]

Hi - I am very new to rc's and have bought a second hand double horse 9088 that appears to have a faulty PCB (one of the voltage regulators appears to be missing so only one motor will turn). I bought a couple of regs and tried these but all that happens is that the motor turns at full revs. Does anyone know where I can purchase a replacement board in the UK/EU. Thanks.

[Burgess]

Hello peeteey and welcome to the forum from Wales.

Are you sure it was a voltage reg that's missing and not a mosfet transistor?

You could try:

These firms that doo DH helis on ebay ‘hobby-power' based in
kidlington, Oxfordshire


Subba's Collectables UK based in Barnsley, South Yorkshire, United Kingdom

Or

Howes Models Ltd Unit 2C/D Station Field Industrial Estate, Kidlington, Oxon, OX5 1LA phone No 01865 848000,
They may either have or know who may stock DH parts.


I've found these links below, those receivers have the RX crystal soldered in place so if you change the receiver board you'll need to obtain an exact match, or swop over the crystal from your old board.

http://www.xheli.com/3-channel-9088-apache-parts.html

http://www.gadgetgalaxy.com.au/Syma%209088%20Apache%203CH%20Helicopter%20Spare%20Parts.htm


Burgess

[peeteey]

Hi Burgess and many thanks for the reply. I will certainly try the companies you have listed.

The reason I thought it was a voltage reg missing was that the images of the board I have seen on the web show 2 and my board only has one.

What does the mosfet transistor do? what does it look like?

Thanks again, Peeteey

[Burgess]

A voltage reg might seem to be the logic choice for speed controller but it's not. MOSFETs are a solid state electronic switches use to turn and off devices such as electric motors dc brushed or brushless.

MOSFETS are one type of FET the number on the device designates is type, suchas package stile and polarity etc. yours will probably be surface mount device.
MOSFET = metal oxide semiconductor field effect transistor.

Go to youtube and watch this series
https://www.youtube.com/watch?v=llXvF6JYj3E&list=PLUmzZYg1_YlBJPmMqJDvfocfQBMZXQ8hi
Electronics 101: MOSFET's

Here's a Hobbyking 80 amp ESC with switching BEC circuit
Three rows of MOSFETs for each output to the brushless motor


The control side, notice the voltage reg (multi-pin output) bottom left, this is a switch mode voltage regulator, just one type of package.



Google search the component number on the FET for the other motor and check its specification they should only cost a few pence for one, try these: http://www.technobotsonline.com/1n5402-3a-200v-rectifier-diode.html, or Maplin and Rapeed electronics
You'll find technobots interesting.


Burgess

[peeteey]

Hi Burgess -

I have realised that a volt reg and mosfet can look the same so have been buying the wrong part so thanks for the pictures they have certainly helped.

I watched the youtube 101 mosfet and although I cannot pretend to understand all the science I can at least appreciate what they do.

Eventually managed to find the code on the mosfet I have and it is 70103h which I cannot find online. Can mosfets be cross referenced so I can get a similar one to add to the board?

Thanks, Peeteey

[Burgess]

Yes equivalents ought to be available, however, you'll need to find the spec for the one you have in order to make an informed choice.
The identification should be letters in front of that number, are there any other letters on the package?


Alternatively try this link
http://www.rctoyworld.co.uk/syma-double-horse-spares-208-c.asp
The double horse 9053 receiver board choice of 27mhz and 40 mhz for £9.99
RC Toy World Located at
3, Cardew Drift, Kesgrave, Suffolk.
Phone: 0845 519 9081
Give them a call and see if it will fit you 9088.

Burgess

[peeteey]

Many Thanks for your help with this. I will let you know how I get on.

Cheers, Peeteey

[peeteey]

Hi Burgess -

I sourced a similar rated mosfet from RS components and low and behold she flies. That was the easy part now I have got to learn to control her.

Again many thanks for your help. I would never have gotten to the root problem without your replies.

Best wishes, Peeteey

[admiral]

Well done Burgess, I'm way out of my depth on electronics side.

[Burgess]

Peeteey,

great stuff! good to hear it's working, now the fun starts.

Burgess

[jani]

Well seeing as the problem started when you tried a part from a different brand, I would try switching back to the stock part before junking your ESC.

__________
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[Burgess]

[eshall]

Hi,

Thanks for the info. I tried to communicate with the protocol people, but they don't even reply to emails. In any event thank you for the reply.


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eshall